Abstract: Long-term scouring by dust-laden airflow in industrial dust removal pipelines causes inner wall wear, leakage, and excessively high pressure drop that increases fan energy consumption. Since existing studies lack quantitative analysis on multi-parameter interactions of Z-type elbows, this study aims to provide a theoretical basis for their wear-resistant and energy-saving design. For Z-type combined elbows in ventilation and dust removal systems, this work adopted a bidirectional coupling method of computational fluid dynamics (CFD) and discrete phase model (DPM) combined with response surface methodology (RSM), established a gas-solid two-phase flow model, used a turbulent model to simulate the gas flow field and Oka erosion model to calculate wall erosion rate (validated with good simulation-experiment consistency). Five parameters (bend-radius-to-diameter ratio, inlet velocity, particle mass flow rate, particle size, and connection-length-to-pipe-diameter ratio) were systematically analyzed for their effects on pipeline erosion and pressure drop. A multi-objective optimization yielded the optimal parameter combination. The results showed that the minimum erosion occurred at a bend-radius-to-diameter ratio of 2~3, while low erosion was observed when the connection-length-to-pipe-diameter ratio was 2~3. Inlet velocity significantly increased both erosion and pressure drop, with the pressure drop tripling at 32 m/s. Erosion and pressure drop increased with particle mass flow rate. Erosion peaked at a particle size of 150 μm, whereas particle size did not influence pressure drop. The first elbow exhibited higher average wear with a wide distribution of erosion, while the second elbow experienced concentrated wear. The optimal combination (connection length ratio of 2.7, bend-radius-to-diameter ratio of 3.6, inlet velocity of 20 m/s, particle mass flow rate of 6×10-5 kg/s, particle size of 208 μm) realized coordinated optimization of low erosion and pressure drop. Findings provide quantitative references for pipeline design/protection and are practically valuable for reducing maintenance costs and system energy consumption.

Key words: CFD-DPM, Z-type combined elbows, response surface methodology, dust removal pipeline, erosion-pressure drop

摘要： 基于CFD-DPM双向耦合模型对通风除尘系统Z型组合弯管进行数值模拟，并结合响应面法(RSM)建立预测模型，分析弯径比(k=R/D)、入口速度(u)、颗粒质量流量(?)、颗粒粒径(dp)及弯头连接长度与管径比(H/D)对最大冲蚀率(EMax)和压降(?p)的影响。结果表明，EMax随k增大先减后增，k=2~3时最小；EMax随H/D增大先减后增，H/D=2~3时较低；EMax与?p均随u显著上升(u=32 m/s时?p增至u=16 m/s时的3倍)；EMax和?p与?呈正相关；EMax随dp增大先增至峰值(150 μm)后下降，?p基本不变。而整体Z型管的最大冲蚀率(EMax)由两弯头协同作用决定，第一弯头平均冲蚀率更高(覆盖范围广)，但第二弯头的冲蚀更集中。基于多目标优化获得兼顾低冲蚀与低压降的最优参数组合为：H/D=2.7, k=3.6, u=20 m/s, ?=6×10-5 kg/s, dp=208 μm，可为除尘系统耐磨节能设计提供依据。

关键词: CFD-DPM, Z型组合弯管, 响应面法, 除尘管道, 冲蚀-压降